Rotary pump



c. CADY ROTARY PUMP Jan; 2, 19%.

Filed Oct. 7, 1938 Patented Jan. 2, 1940 UNITED STATES ROTARY PUMP I Charles L. Cady, Rockford, Ill., assignor of fort per cent to Homer J. Yaw, Rockford, Ill.

Application October 7, 1938, Serial N0. 233,703

3 Claims.

This invention relates to rotary pumps and, I while the present design has been developed with I a special view to the requirements of refrigerators, it will be evident that the same is adapted for use as a pump or compressor in a large variety of other applications. v

A salient feature of the present pump is its provision for cutting down leakage to a minimum and providing for automatic take-up for wear so that the pump will operate efficiency and satisfactorily without requiring attention for a much longer period of time than has been customary in the past. I

The invention will be better understood by reference to the accompanying drawing, in which'-- Figure 1 is a side view of the pump; Fig. 2 is a longitudinal section; Fig. 3 is a crosssection on the line 3-3 of Fig. 2; Fig. 4 is a developed section through the rotor and stator parts taken on the arcuate line 4-4.

of Fig. 3; I

Fig. 5 is a diagrammatic view showing only the two vanes of the rotor and stator in the relationship assumed when the rotating vane is about to pass the stationary vane, and

.Figs. 6 and? are sections on the correspondingly numbered lines in Fig. 5.

The same reference numerals are applied to corresponding parts throughout the views.

The pump comprises a casing 8 having pad portions 9 for securing the pump to a suitable support and having a plug I0 inserted in one end thereof and suitably secured by its flange II .to form the pump stator, the reduced portion I2 being cylindrical and having a flat front face I3 and serving as the stator. I4 is the rotor and is cylindrical like the stator l2 but has a close working fit in the bore I5. The reduced shank- I6 of the rotor is truly concentric therewith and.

supported in a ball bearing H which in'turn is carried in a plug I8 fastened asindicated at I9 onto the end of the casing 8. Drive may be transmitted to the rotor I4 by means ofits shank I6, and what is indicated at 20 may represent the end of a drive shaft suitably connected to the shank I6 for drive purposes. The front face 2I of the rotor I4 is given a helical form. The high point of the helix, as indicated at- 22 in Fig.

4, is disposed in closely spaced relation to the fiat face I3 of the stator I2. At 23 is indicated the drop-off or abrupt descent from the high point p to the low point of the helix. A radially disposed vane 24 is slidable with a close working fit in a radial groove 25 in the rotor I4 and held in fluid-,

tight engagement with the face ll of the stator by means of one or more springs 26 entered in a.

l recess or recesses 21 provided therefor in the rotor I4 in communication with the groove 25. In that 'way I have eliminated the necessity for 5 close fitting of the rotor I4 relative to the stator I2 in order to provide a fluid-tight fit between .the high point of the helical face of the rotor and the fiat face of the stator. The stator and rotor parts are centrally bored in accurate alignl0 ment with one another, as indicated at 28 and 29, to receive a pin 30 with aclose working fit. This'pin is held in place by a plug 3| threaded in the end of the bore 23. The inner end of-the vane 24 is machined'on an are, as at 32, to con- 16 form to the cylindrical shape of the pin 30, and, of course, the outer end 33 of the vane 24 is machined on a concentric arc to conform to the curvature of the bore I 5.

34 and 35designate the intake and exhaust 20 ports in the stator I2 which are in circumferentially spaced relation as indicated in Fig. 3, far enough apart to permit location of the main vane 36 therebetween. This vane is similar to the vane 24 and has a'close working fit in a radial 25 groove 31 provided in the stator I2. One or more springs 38 entered in holes 39 communicating with the groove 31 serve to keep the vane 36 riding with a close fluid-tight fit on the helical face 2I of the rotor H. The formation of the ends 30 32' and 33' of the vane corresponds to the formation of the ends 32 and 33 of the vane 24.

The vanes 24 and 36 are both wedge-shaped longitudinally, opposite sides of each of these vanes being truly radial with respect to the axis 35 of the center pin 30, as indicated at a and b on the vane 24, and at c and d on the vane 36 in Fig. 5. The longitudinal edges of the projecting portions of the vanes 24 and 36am chamfered, as indicated at a, b, c, and d, so that the 40 vane will ride or slide easily past one another in the turning of the rotor I4, while maintaining a good seal at all times. As wear occurs, the

springs'2li and 38 maintain a good seal by keeping the vanes 24 and extended for good sealing en- 4.5

sion of the chamber on the intake side oi the vane as and a corresponding contraction of the chamber on the erdiaust side of said vane in the rotation of the rotor M, as is thought to be selfevident from inspection of Fig. 4, in which the complicated assembling and consequently the pump is available at much lower cost than other pumps with which I am familiar. It will, furthermore, operate for a much longer period satisfactorily without requiring any attention. Obviously, it will involve very little expense to replace both of the vanes whenever that may become necessary.

It is believed the foregoing description conveys a good understanding of the objects and advantages of my invention. The appended claims have been drawn with a view to covering all legitimate modifications and adaptations.

I claim:

1. A rotary pump comprising a casing, stator and rotor elements relatively rotatable in said casing, one having a fiat face and the other a helical form of face in opposing relation thereto with the high point close to but spaced from said fiat face, a spring pressed vane radially disposed relative to said elements and slidable with a close working fit in a radial groove provided therefor in the flat faced element and projecting from said flat face and having slidable sealing engagement on the helical face of the other element, the spring actuation of said vane compensating for wear of the contacting surfaces of said vane and helical face, means providing for inlet and outlet of fluid on opposite sides of said vane, and another spring pressed vane radially disposed relative to said elements and slldable with a close working fit in a radial groove provided therefor in the helical faced element at the high point of its helix and projecting therefrom and having slidable sealing engagement on said fiat face, the spring actuation of said vane compensating for wear of the contacting surfaces of said vane and fiat face while providing the yieldability necessary in the sliding of one vane over the other in the turning of the rotor, at least the leading longitudinal edge portion of the moving vane and the trailing longitudinal edge portion of the other vane being chamfered on their exposed portions substantially as and for the purposes described.

2. A rotary pump comprising a casing, stator and rotor elements relatively rotatable in said casing, one having a flat face and the other a wear of the contacting surfaces of said vane and helicalface, means providing for inlet and outlet of fluid on opposite sides of said vane, and

another spring pressed vane radially disposed relative to said elements andslidable with a close working fit in a radial groove provided therefor in the helical faced element at the high point of its helix and projecting therefrom and having slidable sealing engagement on said fiat face, the spring actuation of said vane compensating for wear of the contacting surfaces of said vane and flat face while providing the yieldability necessary in the sliding of one vane over the being wedge-shaped and having both sides radial, and both of the exposed radial edge portions of both vanes being chamfered.

3. A rotary pump construction comprising a hollow body having a cylindrical bore open at both ends, a plug having a reduced cylindrical pilot portion fitting in and closing one end of said bore, the pilot portion having a fiat inner face normal to the ems of the bore, a cylindrical rotor having a working fit in the bore and provided with a reduced concentric shank portion extending from the other end of said bore for attachment of drive means, a plug forming a closure for the last named end of said bore and carrying an anti-friction bearing fitting on the reduced shank portion of said rotor for support of said rotor in concentric relation with the bore, a center pin coaxially disposed with respect to the rotor and first named plug and having a close working flt in coaxially aligned bores provided therein, said rotor having a helix face on that side toward the flat face of the first plug and annularly' with respect to said center pin with the high point thereof close to but spaced from said fiat face, a spring pressed vane slidable in a radial groove provided therefor in said rotor at the point of the helix for sliding engagement with the flat face of the first plug, and another spring pressed vane radially disposed in a groove pro= vided therefor in the pilot portion of the first plug for sliding engagement with the helix face of said rotor, both of said vanes having concentric arcuate inner and outer ends, the inner arcuate ends having a close working fit on the center pin and the outer arcuate ends having a close working fit in the bore in said body, and said first named plug having an inlet and outlet for fluid on opposite sides of the last named vane.

CHARLES L. error.

other in the turning of the rotor, both vanes 

